SU738635A1 - Method of automatically controlling operation of deslimer - Google Patents

Description

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The invention relates to methods for automatically controlling the operation of cheishamors and can be used in the enrichment of minerals (for example, in the desliming of iron ore concentrates).

There is a known method of automatically controlling the operation of the thickener by changing the flow rate of the condensed pulp depending on the concentration of the solid phase in it with a correction for the rate of sedimentation of the solid phase in the pulp fed to the thickener 1,

The closest to this invention g to the technical essence and the achieved result is a method of automatic control of the operation of the separator, in which a given discharge density is maintained by stabilizing the level of the solid fraction and changing the water flow in the feed slurry line 2.

A disadvantage of the known methods of automatic control of operation of thickeners and separators is that they do not provide high-quality separation of the starting material when changing the flow rate and density of the feeding pulp due to the selective separation of products of a complex solid pulp phase having a different density. For example, to separate sludge quartz particles and concentrated iron oxides (magnetite, hematite, etc.) in the upward flows of the pulp, when the volume and density of the feeding pulp is reduced in known methods, the height of the thickened layer, i.e. 10 of the yellow pulp fraction, which has already passed the separation stage and settled in a dense layer, whereas the material separation has already been carried out earlier in the upstream and was determined

15 speeds.

. The aim of the invention is to improve the quality of the desliming of iron ore slurries with a change in the parameters of the technological process.

The goal is achieved by measuring the rate of the upward flow of the pulp. deslamator and stabilize it by exposure to

25 water consumption in the feed pipe. .

FIG. 1 is a schematic diagram of a system that implements. this method; on .fig. 2 - graphics

30 solid distribution

particles depending on their speed,. sazhdeni.

A method for automatically controlling the operation of the demasher machine is carried out as follows.

The system includes a vat of a deslamator 1, a slurry pipeline 2, a receiving box 3, a dividing partition 4, a supply pipeline 5, a shut-off valve 6, a discharge pipe 7 with a valve 8, a speed sensor 9, its flow rate rising 10, a gauge layer level sensor 10, secondary indicating devices 11 and 12, dials 13 and 14, heads 15 and 16, actuators 17 and 18.

The feed slurry enters along the slurry pipeline 2 and the receiving box 3, in which the flow is directed and guided through an annular discharge slot into the working cavity of the tank of the miller 1. The tank is divided by a cylindrical partition into two communicating vessels. Inside the dividing partition, a solid pulp fraction settles, heading towards the discharge chamber of the vat. At the lower edge of the septum, a portion of the pulp is separated from the downward flow and directed into the upward flow between the partition wall and the wall of the tank to the drain threshold. The value of the required upstream speed must be kept constant and equal to

v. -. -,

. In the finely divided solid phase of iron ore pulp entering dehlamatia, the main components are quartz sand and iron ores — both magnetic and non-magnetic. The dependence of the content of particles in the solid phase of the pulp on their size: pa complies with the normal distribution law. The corresponding graphs of the distribution of the content of solid particles (%). depending on the rate of their deposition, V for quartz particles (curve 1) and iron oxides ("Riva 2) are shown in Fig. 2 ..

It follows from the graphs that with a speed of the upward flow of the pulp equal to the critical V ,,. particles that have a lower speed of fall, the tail ri rides, deformations, and particles that have a deposition rate higher than V,. ttt: in a dense layer of discharge concentrate. The critical velocity V is optimal for the sludge / concentrate separation process. With a decrease in the rate of the ascending flow of a below V | the concentrate is intensively clogged with quartz, i.e. reduced percentage of iron in it. Yri. Increasing the speed of the upward flow above V, a significant part of the finely divided iron goes to the tail merge. Stable rear speed of upward flow.

equal critical, optimization of the process of declaring is achieved.

Practically, the value of V.- depends on -01 distribution of quartz and iron oxides in the size classes for the specific technology of the concentration plant and therefore, in each individual case, the experiment is determined by testing using a sieve and chemical analyzes of the ground solids of the pulp fraction.

The speed of the pulp upstream is measured by a sensor and is recorded by a secondary indicating when j; boron 11. The converted value; the speed into an electrical signal is compared with the task set by unit 13 according to the process requirements, and the Q controller 15 using an actuator 17 and a locking valve 6 sets the additional water flow rate at which the flow rate of the upstream becomes constant for a given value V.,.

five

In addition, when the amount of solids in the feed pulp changes, it is also necessary to control the concentrate discharge rates, maintaining

0, its density is constant and equal to the specified level. For this, the sensor 10 measures the level of the condensed layer and, depending on its height, with the secondary indicating device 12, the regulator 16, the actuator 18 and the valve 8, the cross-section of the discharge nozzle is measured 7 in such a way that the density of the product being unloaded

0 remains constant.

The combined operation of the two automatic control circuits (speed stabilization, during the flow of pulp and stabilization of the zone of constrained compaction) makes it possible to maintain the distribution process in the optimal mode and to ensure the required quality of ores of slurry.

Claims (2)

1. Author's certificate of the USSR And 571284, cl; On 01 D 21/00, 1976. 2. Authors certificate of USSR I 409722, cl. On 01 D 21/02, 1972 (prototype). f phi9.1